Ideal Isar 30100 fan, how to test, coil resistance, 5 wires

[member]

Please can anyone help me with information to test the fan on this boiler?

The display went out and the boiler died. I have replaced the pcb with a refurbished one from http://myworld.ebay.co.uk/compumerv, excellent value at £55, and it was this engineer who said that the fan was probably the cause and needed checking.

I have searched the forum and found one entry saying that a resistance of 108 Ohms was found between red/ blue. Is anyone able to confirm this?

Excluding the earth, the connector has 5 wires. What are the other 3 wires for? Is anybody aware of the normal resistance between each of these others?

Thank you for your help.

 

[gas4you]

Never needed to check resistance on these yet, only voltages.

Can't remember which is which (too lazy and knackered to go out to my van again right now ), but look in your MI's, one pair should be 15v DC, the other pair 325V DC (the power to the fan motor).

Only test this yourself if you are competent to do so as with this voltage it is extra lethal

 

[Kristoflampie]

approximately 130 ohms through the 2 outside terminals on the plug on the fan, yours sounds ok , dont bother about the others they are for speed control according to demand . These pcbs are very bad for packing up for no outwardly obvious reason along with a whole lot of other problems.... not Ideals finest hour!!

 

[member]

Thanks to both of you for your help, I will check this out now, being careful to watch the safety aspect....thanks for the warning!

 

[justqualified]

Not being cheeky but did you put the plastic links in the right places on the pcb when you changed it.

 

[member]

Hey you guys, thanks....it works again. I checked the fan resistance between red/blue and it was about 120 Ohms and so reconnected everything with fingers crossed and, Bingo!
Incidentally, I had a reply from Caradon also who confirmed the fan resistance of about 130 Ohms
About the jumpers, yes, I did check them, following the advice from the supplier (see link above) of the reconditioned pcb. They were very helpful and I would recommend them highly.

 

[dan212]

i have a m3080 .. im getting the same type of problem but after checking the resistance between red and blue(with pcb not connected) i get a reading of around 100 - 110 ohms.. is this an acceptable resistance level or dos the fan needs replacing?

i now have a reconditioned pcb but i havent connected it just in case it blows.
the engineer that suppled the reconditioned pcb checked the old pcb (green resistors) n told me that the fan needs fixing/replacing

i can only think of two options from here.. 1 is to clean out the old fan then reconnect. 2 is to purchase a new fan from ebay for around £60

 

[dan212]

ok so i think i found the problem. i noticed the fan wasnt spinning as much. this was because one of the three upper springs that connect the fan motor to the casing was missing.

so now i need to know if its worth fixing this or is it best to get a new one?

if i was to fix this myself then where can i find the upper springs and a metal disc holder thing from?

second resistance check shows around 108Ohoms between red and blue